1. Field of the Invention
The present invention relates generally to machines used in the nursery and greenhouse industry for extracting seedlings from a first seedling tray or "plug tray" with small seed germination cells and transplanting them into a second tray having growing cells larger than the seed germination cells of the plug tray to encourage continued unimpeded growth of each individual transplanted seedling.
2. Description of the Related Art
In the nursery and greenhouse industry (hereinafter referred to simply as the "growing" industry), seeds are initially germinated and the seedlings resulting therefrom are grown in trays having an array of small compartments or "cells" within the tray. The size of the tray cells are selected to be sufficient large to accommodate the root ball of the plant in the early stages of its development from a single seed into a small seedling while economically making use of the limited space available within a greenhouse or other nursery building. Once the seedlings have germinated and have developed root balls and it is determined that the continued unimpeded growth of the seedling is best continued in a tray having leger room to facilitate this growth, each seedling must be transplanted to a larger tray or pot for further growth and eventual outdoor planting or commercial sale.
The roots of the seedlings will typically form a compact ball with the soil contained within the tray compartments, which allows the seedling and the associated soil to be transplanted as a unit (the seedling "plug"). In the past, seedling plugs have been transplanted by hand into soil filled pots or other trays with larger cells. However, the high cost of labor and the seasonal nature of the growing industry has made manual transplanting undesirable.
Automatic transplanters are known which utilize specially fabricated seedling flats which permit the seedlings to be pressed through the base of a germination compartment into a pot located below. Other known transplanters use cam-driven rotating pairs of plate-like fingers to extract the seedlings, or utilize pre-bent metallic wire fingers which are retained in a straight configuration and injected into the soil surrounding the seedling. These known devices move the germinating tray on an indexable table with respect to the transplanting head of the apparatus.
What is needed is an apparatus of sturdy construction which may readily accommodate germinating trays of varying cell dimensions, and which will rapidly transplant seedlings to larger trays of other cell configurations. The present invention relates to apparatuses and methods of transplanting young plants from seedling trays to larger trays.
In the art to which the invention relates, complicated systems have been developed to transplant plants from a seedling plug tray, where they have initially germinated, to a larger flat tray where they will have more room to grow. These systems have been unduly complicated, and have sometimes injured the seedlings. In the case of a begonia seedling for example, begonia leaves are broad and grow close to the surface of the soil from which the primary stem extends. The prior systems and machines have been known to damage the begonia foliage when the seedling is extracted from the tray in which it germinates originally.
Furthermore, when the user of a transplanting machine wishes to change from one plug tray configuration to a different plug tray configuration, the component of the transplanter responsible for grasping the seedling must also be changed. The changeover of the grasping components is know to be a complicated, time consuming task, often taking several hours and entirely different grasping components. Such delays are undesirable by growers considering time is of the essence when performing their transplanting operations.
It would be desirable to develop a plant transplanting apparatus and method which can quickly and accurately transplant plants from a seedling tray to a larger tray, and facilitate the changeover from one plug tray configuration to another by providing a simple efficient mechanism to remove and reattach the grasping component of the machine. In addition, if a grasping component, often there are several, of the machine fails during operation, it would be advantageous to quickly remove or detach the grasping mechanism from the machine and reattach a replacement in a matter of seconds to further minimize delays in the transplanting process. Thus it would be desirable to develop such an apparatus and method which can transplant seedling plugs without damaging the seedling foliage, and have it adaptable to various sizes and types of trays and plants.